Adhesion and degradation of organic and hybrid organic-inorganic light-emitting devices

Abstract

This paper presents the results of a combined analytical, computational, and experimental study of adhesion and degradation of Organic Light Emitting Devices (OLEDs). The adhesion between layers that are relevant to OLEDs is studied using an atomic force microscopy technique. The interfacial failure mechanisms associated with blister formation in OLEDs and those due to the addition of TiO2 nanoparticles into the active regions are then elucidated using a combination of fracture mechanics, finite element modeling and experiments. The blisters observed in the models are shown to be consistent with the results from adhesion, interfacial fracture mechanics models, and prior reports of diffusion-assisted phenomena. The implications of the work are then discussed for the design of OLED structures with improved lifetimes and robustness.

Micro-wrinkling and delamination-induced buckling of stretchable electronic structures

“…It is assumed that films that are deposited on pre-stretched substrates can delaminate due to buckling, 25 sandwiched particles and voids. 24…”

“…This failure mode can also occur due to merging of the possible micro voids that can lead to delamination. 19,21 Interfacial cracks are also formed from sandwiched dust particles 23 and bubbles 24 between the deposited films and substrates. Residual stress can also drive the delamination of the layered a)…”

Adhesion in flexible organic and hybrid organic/inorganic light emitting device and solar cells

“…There is also a potential for improving charge transport via incorporation of nanoscale titanium dioxide (TiO 2 ) particles into the active layers of organic solar cells and light emitting devices. 6 In the case of organic solar cells, the results show that, in selected cases, the device performance may be improved, depending on the morphology and sizes of the nanoscale TiO 2 particles. 6 McGehee 7 has explored the fabrication of highly efficient hybrid solar cells with improved exciton and charge conduction in the bulk heterojunction solar cells.…”

Cold welding of organic light emitting diode: Interfacial and contact models

“…2,27,33,[43][44][45] Prior measurements of adhesion energies are presented Table II and Figure 8. These show that the computed energy release rates (Figure 8) can exceed the measured adhesion energies (Figure 7) obtained in the interfaces that are present in OLED structures.…”

“…22,[27][28][29] As the beam deflects, the cantilever beam (layer 2) makes contact with the adjacent layer (Layer 1), as shown in Figure 1(b). This results in surface contact that increases with increasing pressure (Figure 1(c)).…”